The present invention relates to a portable power generator. A portable power source needs to be light, easy to use, and produce sufficient power in a form that is useful. Over the last twenty years, numerous mobile devices including cell phones, smart phones, laptops, GPS navigation, mp3 players, digital cameras, and camcorders have all been developed. They are all limited by their battery life and would benefit from a portable power source.
Devices exist that are full sized generators. Their size precludes them from being portable or pocket sized. They are also more expensive. Some have a low voltage DC interface with several problems. They have to interface directly with numerous mechanical and electrical interfaces such as diverse types of plugs. If underpowered, they can trickle charge but this extends the charging time. Some have an AC interface. This can only be achieved with more expensive electronics and/or large heavy components like transformers or larger generators and with lower conversion efficiency.
The electrical output of “mini dynamos” is, by virtue of their small size, low power and low voltage. Devices in existence today have used mini dynamos to product low voltage DC to directly trickle charge batteries for flashlights and some cell phones. As stated above, the benefit of low voltage DC is the DC interface will allow an underpowered source to trickle charge. Their two drawbacks are (1) their underpowered generators extend the cranking time needed to charge, and (2) the low voltage DC interface has to support many DC interfaces. This limits the usefulness of these devices to one dedicated application or a limited number of them with attachments for each interface. The present invention, by contrast, uses one or more dynamos and overcomes the difficulties involved in converting a low power AC source to drive the chargers for a complete range of applications.
Applicant is aware of the following prior art:
U.S. Pat. No. 6,522,040 to You discloses a mechanism for translating human power input to rotation of a generator including multiple gears stepping up the speed of revolution. From FIG. 11 of You, it is apparent that You generates a low level DC voltage since its output is directly connected to a cell telephone coupling.
Published Application No. US 2005/0200221 A1 to Vasilovich et al. discloses an apparatus for converting human power to electrical power. Vasilovich et al. disclose generation of 110 VAC power as well as 110-120 AC/DC inverter output. However, the disclosure at paragraph [0069] specifically describes the inverter 27 as converting direct current electrical energy into alternating current electrical energy.
U.S. Pat. No. 6,788,504 to Vanderkolk discloses conversion of DC power to single phase power as well as typical household outlets as shown in FIG. 2 thereof. Vanderkolk teaches an output of 110 VAC.
U.S. Pat. No. 5,949,215 to Takakura discloses a small size battery charger that operates through rotation of a handle. Takakura fails to teach or suggest generation of high DC voltage.
U.S. Pat. No. 6,930,403 to Hartman et al. discloses a mobile electrical power source including a crank assembly that is rotated to generate power. Hartman et al. do not teach or suggest generation of high DC voltage.
U.S. Pat. No. 7,129,592 to Yetter teaches a further example of a human powered electrical energy source in several embodiments. Yetter discloses either generation of DC voltage or AC power. The AC power may be single or three phase (column 4, beginning at line 62).
Other portable power sources are disclosed in U.S. Pat. Nos. 4,412,355 to Terbrack et al.; 6,281,594 to Sarich; 6,963,186 to Hobbs; 7,292,006 to Horiuchi; 7,327,046 to Biamonte; 7,411,371 to Hobbs; as well as Published Application Nos. US 2007/0285053 A1 to Noguchi et al. and US 2008/0157536 A1 to Bulthaup et al.
The present invention differs from the teachings of the prior art listed and discussed above by providing a portable, compact, efficient and cost-effective power source made up of singular or multiple generators that is/are human powered, provides an output of 120-240 volts DC, and includes a home-type electrical receptacle so that the typical charger used with portable devices may easily be plugged in and used.